The invention relates to an electric commutator with several switch ways distributed about a vertical principal axis of the actuator.
Recent developments and the rapid evolution of telecommunication means, such as mobile telephones, laptop computers and other devices require more control. One type of control requires moving accurately and quickly a cursor on a screen. The equipment requires electromechanical components of reduced dimensions and the need to allow the scanning of menus, the movement of a symbol on a screen and, more generally, the combination in a single component of several electric switching functions.
It is especially desirable, in the case of an application to a mobile telephone (for example GSM or UMTS), whose dimensions are increasingly reduced, and that must be able to be handled and controlled by the user with one hand, that such a multiple switch should be able to be manipulated with a single digit, for example the thumb, while being implanted on the main front face of the telephone comprising in particular the keypad, or on one of the two main lateral edges of the telephone casing, or under the main face of the telephone.
The requirement for a compact and very small-dimensioned control device making it possible to move a cursor on a screen, and/or to scroll menus (Scanning), also called a “browser”, is increasingly important on apparatus of the “mobile telephone” or “Personal Digital Assistant” type offering an increasing number of functions and services in particular requiring choices proposed on one or more screens, similar to the use of a laptop computer, or else portable items of apparatus processing digitized sound files, for example according to the “MP3” standard.
It is therefore desirable to have an electric commutator with multiple switch ways making use of a single actuation member that can be operated with one finger.
Such operations, for example by means of the underside of the thumb of the hand that holds the apparatus, must be easy and be able to be carried out in the largest possible number of directions, with very great user-friendliness and low operating forces (less than 2 Newtons).
In addition, such a miniaturized component must provide its user with a tactile sensation reflecting the validity of the operations carried out.
The tactile sensation transmitted by the commutator to the user is a very important parameter for its performance and its user-friendliness.
Document FR-A-2.875.024 describes an electric commutator comprising an element making it possible to generate a tactile sensation that is similar to a “click” of a conventional button, in response to a control action applied by the user to the commutator.
According to this document, the upper face of the upper panel is divided into several contact zones, with each of which the control element is capable of coming into contact. The commutator also comprises an electric commutator that is associated with each contact zone and that is actuated when the pointing element comes into contact with the associated contact zone.
Thus, the commutator comprises a number of switches that is equal to the number of contact zones, which causes connection problems, and an increase in the total cost of the commutator when the commutator comprises a large number of switches.
Document U.S. Pat. No. 6,686,906 describes an electric commutator comprising four switches that are arranged so that the upper face of the upper panel is divided into nine contact zones, and so that, when the pointing element is in contact with one or other of the contact zones, one or more switches are actuated.
According to said document, each switch comprises an element in the shape of an inverted dome that forms a disengageable stop of the upper panel, and that is capable of suddenly changing state when it is actuated to establish a switch way of the commutator. In addition, when contact of the pointing element with the upper panel is broken, the dome-shaped element deforms suddenly to resume its initial shape.
Each sudden change of state of this dome-shaped element is felt by the user manipulating the pointing element in the manner of a “click” of a button.
Consequently, when the pointing element comes into contact with a contact zone that is associated with two switches, the two dome-shaped elements of these two switches change state.
The state changes of the two dome-shaped elements are not usually simultaneous. The tactile sensation that is then felt by the user corresponds to two consecutive state changes, while the user has just applied a single control action; this may distract the user in his use of the electronic apparatus.